Electricity usage monitoring

[iep]

Thanks. I'm finding my feet with this. Is 'Home Assistant' the Shelly app or a compatible third party app?

Ohhh, and to be totally clear. I'd need to buy the Shelly EM, 120A clamp and that's it? I'm assuming the app is free.

 

[pcaouolte]

You buy a SHelly EM with a 120A clamp. You will probably also need a separate electrical box to fit the shelly inside to enclose it safely. You need enough electrical knowledge to be able to wire it up safely.

The Shelly app is free but gives you less information than I showed above. I can't easily get screen shots from the shelly app onto here at the moment. It does show current usage and some historic graphs.

Home Assistant is a separate free app which runs on a Raspberry Pi (or various other low power computers) and is designed for home automation. It can also record data from lots of different sources and is very customisable. The charts shown above came from Home Assistant.

 

[iep]

You buy a SHelly EM with a 120A clamp. You will probably also need a separate electrical box to fit the shelly inside to enclose it safely. You need enough electrical knowledge to be able to wire it up safely.

The Shelly app is free but gives you less information than I showed above. I can't easily get screen shots from the shelly app onto here at the moment. It does show current usage and some historic graphs.

Home Assistant is a separate free app which runs on a Raspberry Pi (or various other low power computers) and is designed for home automation. It can also record data from lots of different sources and is very customisable. The charts shown above came from Home Assistant.

Great, thanks. I'm happy working with wiring and actually have a spare electrical box right next to the main incomer to our boards.

I don't have the Pi unfortunately. There's a home assistant app for IOS but I doubt it's the same thing.

Either way, seem like this is a decent enough solution for what I need.

 

[ericmark]

I use the Energenie MiHome because it needs a hub and I have a hub used for different things, the plug in module gives the following

To be frank there is more information given on the non PC connected version, in the main I use to monitor when some thing has completed, battery charge etc. I do check freezers to see how long they run for, see if insulation has failed, but once the first month or some had gone, they were really no more than toys.

 

[Alec_t]

Our usage is 4x typical for a representative household so I'm guessing there is a single culprit using more than I'd imagine.

Can't you just
1) switch everything off at the CU,
2) read the meter,
4) switch on item 1,
5) read the meter after a known delay,
6) switch on item 2,
7) read the meter after another known delay,
8) etc.
That should identify the culprit.

 

[jj4091]

Sure, but if you need to measure your actual consumption to debug an unexpected behaviour, they are very useful.

Your bill does that every month surely.

 

[iep]

Can't you just
1) switch everything off at the CU,
2) read the meter,
4) switch on item 1,
5) read the meter after a known delay,
6) switch on item 2,
7) read the meter after another known delay,
8) etc.
That should identify the culprit.

Sure, if time were no issue and the culprit were running continuously, this would work perfectly well.

Unfortunately, I have 18 circuits. Observation time to get adequate resolution would need to be ~1 hour which would mean 18 hours without power to collect the full set. If I then want to find which consumer on each circuit is drawing the current, I'd need to repeat the process.

This assumes that the culprit is actually on during the observation period. It would be very easy to monitor for an hour and miss the high current event.

 

[iep]

Your bill does that every month surely.

Not sure I follow?

I know we have high consumption (from the bill) but now I need to figure out what is causing it (whether that be a device consuming high power or a habit within the household).

I don't see how the bill helps with the latter?

 

[Harry Bloomfield]

Not sure I follow?

I know we have high consumption (from the bill) but now I need to figure out what is causing it (whether that be a device consuming high power or a habit within the household).

I don't see how the bill helps with the latter?

Start with teenagers, if there are any in the house

 

[ericmark]

I'm guessing there is a single culprit

This means once found likely the equipment you buy will no longer be required, so what I would look for is what else it can do, I would be leaning towards a clamp on meter, but maybe because for some years I have wanted a new one, the one I had was bought many years ago in the last century when working in Hong Kong before the take over, and was current AC only.

Looking on ebay found this at £11 not much more expensive than a multi-meter without clamp on, over the years even measuring voltage being able to use the clamp to hang it on things made it a easy to use meter.

I have hardly used the wireless clamp ammeter I got free from the electric supplier, the current transformer has a battery in it and splits to fit it, it was calibrated as watts, clearly at 230 volt, but it did not log the data, so no different to clamp on ammeter really except wireless.

 

[BobCroft1]

One of the very best resources for information on power monitoring in the UK is the Open Energy Monitor project. The website is very comprehensive and informative. They sell equipment to do dometic electricity monitoring as the OP desires. They also provide all the imformation to build ones own monitoring systems. The have an on-line database called emoncms which can chart the data in any way desired.
I also use Home Assistant and it is possible to integrate any energy monitor into it. Extremely flexible!! but has a learning curve. FWIW I built my own monitoring devices. Apart from the European made Shelley I would be very wary of some of the alternative current / voltage measuring devices, such as those from the Far East, as they very likely do not comform to UK electrical safety standards.

 

[iep]

Okay, made some progress on this:

1. The Shelly EM and clamp turned up and I was able to hook them up and get the app working without any hassle (YMMV). Actually quite an impressive little device. Physical installation was trivial (put it on an unused lighting circuit from the consumer unit) and attached the provided clamp. Mounted it all in an electrical box. Installed the app on my phone (IOS) and created an account. All went smoothly. The bit that really impressed me though was when I turned on the power to the Shelly EM and asked the app to find it. The device showed up immediately without any required input on the app and, after providing wifi password, started providing measurement data. Couldn't have worked more smoothly. Chuffed.

2. I've found the culprit of our high electricity usage! Initially, I was stumped. The base load of the house was 200W which is a little higher than an average UK house but I was able to account for it all fairly easily (stuff on standby that we can start habitually turning off). Critically though, a 200W base load did not account for the high usage we seem to have.

I observed all evening with nothing unexpected happening. Went to bed and, in the morning, found that something had been intermittently drawing 3kW during the night. After that it was easy to find. There's only a couple of things in the house that can draw that kind of power. I initially asked the dog if she'd been making toast during the night (apparently not, no thumbs) so looked elsewhere. Turns out the electric underfloor heating we have in the kitchen has been turning on during the night. The controller says it is off (we never use it) but it seemingly has some 'night mode' or minimum temperature threshold below which it will still switch on. Easy solution, switched it off at the mains outlet. Since then, no intermittent 3kW usage.

So, hopefully that'll make a difference. Sure the kitchen will theoretically be a bit colder in the morning but the house thermostat will take care of that (definitely better to heat with the boiler than electric).

Could I have worked this out without the Shelly? Yeah, probably but it would have taken me a lot more time/effort since I'd have needed to do one circuit or major appliance at a time.

I suspect it'll pay for itself pretty quickly. Recommended for this type of debug.

 

[BobCroft1]

That's good feedback and I am glad you found the issue. It reminded me of a job I did years ago when a customer complained of an unaccounted use of electricity. It turned out the previos property owners had installed heating in the dog kennel!! Turned that off and bingo, happy customer.

 

[iep]

That's good feedback and I am glad you found the issue. It reminded me of a job I did years ago when a customer complained of an unaccounted use of electricity. It turned out the previos property owners had installed heating in the dog kennel!! Turned that off and bingo, happy customer.

That's awesome. To be fair, our dog won't even go outside on days like today.

Only downside of the app is that I can now actually see how much electricity my family waste by leaving stuff switched on!!!!! It's turning me into a grumpy old man.